Flashlights



July 16, 1963 G. SCHMIDT ETA;

FLASHLIGHTS Filed sept. 1e, 1960 Inventors Kum/wl M 27" WMM UnitedStates Patent O 3,097,798 FLASHLIGHTS Gerhard Schmidt, Berlin-Frohnau,and Heinrich Feindt, Berlin-Grunewald, Germany, assignors to LicentiaPatent-Verwaltungs-G.m.b.H., Frankfurt am Main, Germany Filed Sept. 16,1960, Ser. No. 56,577 Claims priority, application Germany Oct. 14, 19592 Claims. (Cl. 240--10.65)

The present invention relates to flashlights.

There exist llashlights equipped with connector prongs that enable thellashlight to be connected to a source of electrical energy for thepurpose of recharging the flashlight batteries.K In flashlights of thistype, ditiiculties have arisen insofar as the problem of heat insulationis conce1-ned. Tha-t is to say, some of the component parts are not onlybetter able to withstand heat than others but are, in fact, heatgenerators, so that those part-s which are less well able to withstandheat must be insulated ffrom the heat generators. Such heat generators,in a portable flashlight, are the bulb or lamp as well as the currentlimiting resistors which are interposed between the connector Iprongsand the recharging unit which is connected to the batteries Vand whichconverts the standard A C. or D.C. house voltage of 110 to P20 v. to adirect voltage of an amplitude suitable for charging the batteries.

Furthermore, in flashlights having prongs that enable the device to beconnected to an outside source of electrical energy, these prongs areusually covered by a cover which is removably mounted on the ilashlightcasing, the arrangement bein-g lsuch that the lamp is carried by thiscover so that the 4lamp is physically as Well as electricallydisconnected from the flashlight casing whenever the cover is removed inorder to expose Ithe prongs. It is, therefore, essential that theelectrical contacts whichy place the lamp in circuit 'with the othercomponents of the flashlight circuit be especially designed to withstandthe repeated connecting and disconnecting that takes place whenever thebatteries are -to` be recharged. `Contacts 'which will fulll this needare not only complicated and expensive, but must be manufactured with ahigh degree of accuracy in order t-o insure the making of a goodelectrical contact every time the cover carrying the lamp is replaced onthe flashlight casing.

It is, there-fore, an object of the present invention to provide aportable flashlight which overcomes the above disadvantage.

It is :another object of the present invention to provide a ashlight inwhich those components of the flashlight circuit which are best able towithstand heat are all located in the same general area within thellashlight casing.

It is still another object of the present invention to provide aflashlight in which the lamp is permanently connected to the flashlight.at the same end of the casing `from which the prongs project, and inwhich the cover :adapted to cover these prongs does not cause the lampto be removed whenever the tlashlight batteries :are .to be recharged.

The objects of the present invention also include the provision of aas'hlight which is of compact construction and which may readily bemanufactured at low cost,

With the above objects in view, the present invention resides mainly ina flashlight which comprises a casing having a longitudinal axis andapartition transverse to lthe axis and dividing the interior of thecasing into two sections, a rechargeable battery arranged in saidcasing, a recharging unit :also arranged in the casing and electricallyconnected to the battery, a pair of prongs electrically connected to therecharging unit and enabling the lflashlight to be electrically andmechanically connected .to a source of electrical energy, a coverremovably mounted on the ICC easing for covering the pron-gs when thesame are disconnected from the source of electrical energy, a lamparranged generally between the prongs and occupying along thelongitudinal axis of the casing a position spaced inwardly from the freeouter ends of the prongs, and resistor means electrically interposedbetween the prongs and the recharging unit and occupying in the casingapproximately the same position along the longitudinal axis .as does thelamp. The lamp and the resistor means are located on one of the twosections of the casing while the rechargeable battery and the rechargingunit are located in the -other section of the casing, so that the heatIgenerating components of the flashlight are grouped .together in oneplace and the heat-sensitive components of the flashlight are groupedtogether in another place.

Additional objects and advantages of the pr-esent invention will becomeapparent upon consideration of the yfollowing description when taken inconjunction with the accompanying drawings, in which:

FIGURE 1 is a sectional view of one embodiment of la flashlightaccording to the present invention;

FIGURE 2 is a sectional view ltaken along line 2 2 of IFIGURE l;

FIGURE 3 is a sectional view taken along line 3-3 of FIGURE l;

FIGURE 4 is a sectional view similar to FIGURE l, except that thecurrent limiting resistors are shown as being differently oriented; and

FIGURE 5 is a schematic circuit diagram of the electrical components.

Referring now to the drawings and to FIGURES 1 to 3 thereof inparticular, there is shown a flashlight having a casing composed of twointert-ting cup-shaped parts l1 and 13, the part 1 containing one ormore rechargeable batteries 2 land a recharging .unit 3 while the part113 carries a pair of connector prongs 4 by means of which thellashlight can be plugged into a conventional outlet box.

The part 13 is formed in its center and between the prongs 4 with adepression 13a having an opening through which a lamp or .bulb 6 isinserted. The lamp is engaged by contact springs 18 and 19 mounted on asupport plate 15 extending transversely across the interior of thecasing and dividing this interior into two sections, there beingVabutment :blocks 14 which may press against the contact springs. Thesocket `actu-ally mounting the lamp 6 is of conventional constructionVand is, therefore, not shown in detail.

The contact spring 18 is connected to a line 17, whereas the contactspring 19 extends into a movable switch contact portion 11 whichcooperates with a station-ary switch contact portion 12, the latterleading to a line 1-6. The switch is actuated by an actuating slide 1t)which has a serrated hand piece 9 projecting through a cutout 7a of acover 7, this cover being removably mounted on the casing and coveringthe prongs 4 when the same lare not in use, Thus, the switch 11, 12 maybe closed by moving the slide 9, 10 downwardly, and be opened by raisingthe slide upwardly. When the cover 7 is removed, the slide 9', 10 willbe carried along and withdrawn from the casing so that the switch 11, 12can not be inadvertently closed while the prongs 4 are received in Ianoutlet box.

As show-n in the drawing, the cover is formed with an inwardly taperingportion `8 which is in alignment with the lamp 6V and protrudes somewhatinto the depression 13a of the casing. In order to improve the lightingcharacteristics, the portion 8 is fashioned asa reilector. Alternativelyor additionally, the portion 8 may contain a suitable optical focusinglens 5.

The il-ashlight casing further contains resistor means which areinterposed between the prongs 4 and the recharging unit 3 in order tolimit the charging current. The resistor means comprise two pairs ofresistors 20,

21 and 22, 23 which are connected in a series-parallel circuit, i.e.,the two resistors of each pair being connected to forni a parallelcircuit which itself is serially connected to -a respective prong 4, asshown in FIGURE 5, which illustrates the electrical connections of thevarious component parts, these connections not being shown, for purposesof clarity, in FIGURES 1 to 3. It will be noted that the recharging unit3 is depicted as a rectifier bridge circuit incorporating four rectifierelements 3a.

As stated above, the lamp and the resistors are the elements bestcapable of withstanding heat and, as is shown in FIGURES l to 3, thesecomponent parts are arranged in the same general area within theashlight casing. Thus, the lamp 6 is arranged generally between theprongs 4 and occupies along the longitudinal axis of the casing,indicated by the dotted line x, a position spaced inwardly from the freeouter ends 4a of the prongs 4, and the resistors 2t), 21, 22 and 23occupy within the casing lapproximately the same position along thislongitudinal axis x as does the lamp `6. As a result, the lamp 6 andresistors 29, 211, 22 and 23 are all in close proximity to each otherand are separated by the transverse support plate 15 from the spaceoccupied by the recharging unit 3 and the batteries 2. In this way, thespace is utilized with maximum eiciency; also, the recharging unit 3 andthe batteries 2 are more easily heat-insulated than would be possible ifthese component parts were so arranged within the casing as to be closeto the lamp 6 and the resistors 20, 21, 22 and 23.

The resistors are so oriented that the axes y of the resistors 20 and 21lie in `a plane forming a right angle with the plane containing thelongitudinal axis x land the two prongs 4, and that the axes y of theresistors 22 and 23 lie in another plane which also forms a right anglewith the plane containing the longitudinal axis x land the two prongs 4.In the embodiment of FIGURES y1 to 3, the axes y of the resistors areparallel to the longitudinal axis x, whereas in the embodiment of FIGURE4, which is otherwise identical to that of FIGURES l to 3, the axes yform right angles with the aforo-mentioned plane containing axis x Iandthe prongs 4.

We claim:

1. In a ashlight incorporating a casing having a longitudinal axis and apartition transverse to said axis and dividing the interior of saidcasing into two sections, a rechargeable battery arranged in saidcasing, a recharging unit also arranged in said casing `andelectrical-1y connected to said battery, ya pair of prongs electricallyconnected to said recharging unit and enabling the flashlight to beelectrically and mechanically connected to a source of electricalenergy, and la cover removably mounted on said casing for covering saidprongs when the same are disconnected from the source of electricalenergy, the improvement which comprises: a lamp arranged generallybetween said prongs and occupying along said longitudinal axis of saidcasing a position spaced inwardly from the free outer ends of saidprongs, and resistor means electrically interposed between said prongsand said recharging unit and occupying in said casing approximately thesame position along said longitudinal axis as does said lamp, said lampand said resistor means being located in one of said sections of saidcasing, said rechargeable battery and said recharging unit being locatedin the other of said sections of said casing, whereby the heatgenenating components of the flashlight are grouped together in oneplace and the heat-sensitive components of the flashlight are groupedtogether in vanother place.

2. A flashlight comprising, in combination: a casing having alongitudinal axis and a partition transverse to said axis and dividingthe interior of said casing into two sections; a rechargeable batteryarranged=in said casing; a recharging unit also arranged in said casingand electrically connected to said battery; a pair of prongselectrically connected to said recharging unit and enabling theilashlight to be electrically and mechanically connected to a source ofelectrical energy; a cover removably mounted on said casing for coveringsaid prongs when the same are disconnected from the source of electricalenergy; a larnp arnanged generally between said prongs and occupyingalong said longitudinal axis of said casing a position spaced inwardlyfrom the free outer ends of said prongs; and resistor means electricallyinterposed between .said prongs and said recharging unit and occupyingin said casing 'approximately the same position along -said longitudinallaxis `as does said lamp; Said lamp and said resistor means beinglocated in one of said sections of said casing and said rechargeablebattery and said recharging unit being located in the other of saidsections of said casing, whereby the heat generating components of theflashlight are grouped together in one place and the heat-sensitivecomponents of the flashlight are grouped together in another place,thereby utilizing the space within said casing with maximum eiciency andfacilitating heatinsulation of said heat-sensitive components.

References Cited in the tile of this patent UNITED STATES PATENTS2,873,358 Dunker Feb. 10, 1959 2,880,306 Witte Mar. 31, 1959 FOREIGNPATENTS 813,863 Germany Sept. 17, 1951 566,286 Canada Nov. 18, 19581,211,940 France Oct. 12, 1959

1. IN A FLASHLIGHT INCORPORATING A CASING HAVING A LONGITUDINAL AXIS AND A PARTITION TRANSVERSE TO SAID AXIS AND DIVIDING THE INTERIOR OF SAID CASING INTO TWO SECTIONS, A RECHARGEABLE BATTERY ARRANGED IN SAID CASING, A RECHARGING UNIT ALSO ARRANGED IN SAID CASING AND ELECTRICALLY CONNECTED TO SAID BATTERY, A PAIR OF PRONGS ELECTRICALLY CONNECTED TO SAID RECHARGING UNIT AND ENABLING THE FLASHLIGHT TO BE ELECTRICALLY AND MECHANICALLY CONNECTED TO A SOURCE OF ELECTRICAL ENERGY, AND A COVER REMOVABLY MOUNTED ON SAID CASING FOR COVERING SAID PRONGS WHEN THE SAME ARE DISCONNECTED FROM THE SOURCE OF ELECTRICAL ENERGY, THE IMPROVEMENT WHICH COMPRISES: A LAMP ARRANGED GENERALLY BETWEEN SAID PRONGS AND OCCUPYING ALONG SAID LONGITUDINAL AXIS OF SAID CASING A POSITION SPACED INWARDLY FROM THE FREE OUTER ENDS OF SAID PRONGS, AND RESISTOR MEANS ELECTRICALLY INTERPOSED BETWEEN SAID PRONGS AND SAID RECHARGING UNIT AND OCCUPYING IN SAID CASING APPROXIMATELY THE SAME POSITION ALONG SAID LONGITUDINAL AXIS AS DOES SAID LAMP, SAID LAMP AND SAID RESISTOR MEANS BEING LOCATED IN ONE OF SAID SECTIONS OF SAID CASING, SAID RECHARGEABLE BATTERY AND SAID RECHARGING UNIT BEING LOCATED IN THE OTHER OF SAID SECTIONS OF SAID CASING, WHEREBY THE HEAT GENERATING COMPONENTS OF THE FLASHLIGHT ARE GROUPED TOGETHER IN ONE PLACE AND THE HEAT-SENSITIVE COMPONENTS OF THE FLASHLIGHT ARE GROUPED TOGETHER IN ANOTHER PLACE. 